1. Field of the Invention
The present invention relates to an actuator controlling device, a drive system, video device, an image projection device, and an actuator controlling method.
2. Description of the Related Art
A piezoelectric element is known to exert a so-called inverse piezoelectric effect that when applied with voltage in a direction of electrodes, deforms, i.e., contracts in proportion to an electrical potential of the applied voltage. Conventionally, there is developed a piezoelectric actuator that transmits a driving force to a driven body by using such a piezoelectric element.
A piezoelectric element used in a piezoelectric actuator exerts a driving force in a state of being polarized in one direction, for example, like a permanent magnet; its driving force can be obtained by connecting the output of a drive circuit to between electrodes installed on both end faces of the piezoelectric element in a polarization direction. The above-mentioned polarization is obtained by continuing to apply a constant voltage for a predetermined period of time in consideration of the composition of the element. The element which has had polarization is driven by being applied with voltage in between a direction of the voltage that has caused the polarization and zero in general.
In general, there is an inconvenience such that the driving sensitivity of piezoelectric elements in an actuator in relation to voltage applied thereon (for the same notion, hereinafter referred to as the driving sensitivity of an actuator) changes by an manufacturing error, aging degradation, and a surrounding environmental condition such as a temperature and therefore varies among devices. Among devices various in driving sensitivity, there may be a device in which the driving sensitivity deviates from a normal range in relation to applied voltage. Therefore, there are potential troubles such that the devices have different display positions and such that the aspect ratio of images is not normal.